I will say replacing the ABS unit was easier than I thought. That said I went for a ride a couple of days ago, applied the rear brake for a sharp turn in a gravel parking lot, the rear brake traveled way farther than expected and probably has air in it again. I got 1,300 miles before the problem resurfaced. I have changed the master cylinder, caliper and ABS unit. Sure maybe the used ABS unit has the same problem but at $100 a copy it seems a bit much to keep trying used ones till I get a good one. I am going to plug the rear brake port in the ABS unit this winter and run a brake line from the master cylinder to the caliper. No rear ABS but at least I will be able to trust the brake. Today I will bleed it again in case I get a chance to ride before white stuff covers the ground.